Britain is one of the most “racially diverse in Europe,” according to the set-piece speech given by British Prime Minister Theresa May last week.

However, the brutal assault of a 17-year-old Iranian-Kurdish asylum-seeker has caused great shock to the country and shined a spotlight on its attitude towards migrants and refugees.

According to the police, last Friday, Reker Ahmed was attacked by a group of between 20 and 30 people in London in a “suspected hate crime assault.”

He was thrown to the ground and repeatedly punched and kicked, which left him with serious head injuries, he remains in hospital. Ahmed arrived in the U.K. without by his parents.

NBC News was told on Tuesday by Scotland Yard that 12 people between the ages of 13 and 24 were charged with “violent disorder” and a 17-year-old boy was charged with “violent disorder and racially aggravated grievous bodily harm.”

Condemnations from politicians:

Gavin Barwell Conservative lawmaker for Croydon Central, call the attackers “scum” on Twitter over the weekend.

While Diane Abbott, opposition Labour lawmaker, said: “With right-wing politicians across the world scapegoating migrants, refugees and others for their economic problems, we are seeing a deeply worrying rise in the politics of hate. We must make clear that there is no place for anti-foreigner myths, racism and hate in our society.”

London’s mayor Siddiq Khan, a Muslim and the son of a British Pakistani bus driver, has also provided relief for a city shocked by the viciousness of the attack. He said in a statement: “We don’t just accept our differences, but we embrace and celebrate them.”

The country’s reaction to refugees:

The heated debate over Britain’s referendum to leave the European Union last year, had immigration and the number of foreigners entering the U.K. as a key topic.

Nigel Farage, the leader of the U.K. Independence Party, was pictured in front of a poster depicting a line of migrants under the heading “Breaking Point: The EU has failed us all.”

According to an Ipsos MORI poll, 26% of respondents felt that immigration was the most important issue in Britain, behind Brexit and the state of the National Health Service.

Migrants is also a frequent topic in tabloid newspapers that have run several stories on alleged asylum-seeker and migrant transgressions in recent years.

Former Prime Minister David Cameron caused criticism after referring to a “swarm” of people who wanted to enter the U.K. when talking about migrants at the French port of Calais.

Such language, some believe, set an unhelpful tone for the debate.

“The way that migrants and asylum seekers — and Muslims in general — are spoken about in the tabloid press leaves a lot to be desired,” according to Miqdaad Versi of the Muslim Council of Britain. “There’s clearly an issue here with the way they are reporting about these minority groups.”

Last year, a report by the Council of Europe’s European Commission against Racism and Intolerance (ECRI) found that although the U.K. has generally strong legislation against racism and racial discrimination, there was “considerable intolerant political discourse focusing on immigration and contributing to an increase in xenophobic sentiments.”

Another report by U.K.’s Institute of Race Relations found an increase in incidences of violence against Polish migrants and racist graffiti after the “Brexit” vote to leave the European Union.

Surprise and shock:

Surprise and shock were the dominant responses towards the attack in Croydon. Ria Houston, 33, who grew up just outside Croydon, said: “[Asylum seekers] are people in need of help so we’ll help them.”

While Daniella Larking, 25, said: “There’s a strong sense of community. It’s really surprising to see something like that happen around here.”

Those investigating the case have echoed the same sentiment. “A number of people came to the aid of the victim as he lay unconscious and injured following the assault,” said Detective Inspector Gary Castle, from Croydon CID. “All communities stand together against hate. No one should be subjected to violent behavior, especially those who have come to London to seek refuge and a place of safety.”